Tornado-flow apparatus for separating particulate substance from gases, particularly adhesive liquids from gases

ABSTRACT

A tornado-flow apparatus for separating particulate substances, especially adhesive liquids, from gases, comprises a cylindrical separator vessel with an axial clean-gas outlet, a gas inlet duct coaxially opposite the outlet and tangential gas inlets obliquely opposed to the flow direction of the inlet duct for producing in the vessel a tornado flow which causes the particulate substance to be separated from the gas and carried outwardly into an annular interspace surrounding the axial inlet duct. Nozzle devices are provided for producing a veil of liquid in the tornado chamber or on the inner wall surface of the chamber. Preferably the nozzle devices comprise a spray nozzle coaxially mounted in the mouth of the inlet duct so as to produce a conical veil of liquid in the lower region of the vessel; and tangential nozzle means in the upper region of the vessel inject liquid to wet the inner wall of the vessel.

Unite States Hoffmann et a1.

atem

[ 1 Feb. 15, 1972 Inventors:

Assignee:

Filed:

Appl. No.:

Alfred Hoffmann, Forchheim; Heinrich Klein, Erlangen, both of GermanySiemens Aktiengesellschait, Berlin, Germany Mar. 11, 1969 Int. Cl Fieldof Search ..55/235-238, 456459,

US. Cl ..55/236, 55/238, 55/242,

55/457, 55/459, 261/79 A ..B01d 47/06 References Cited UNITED STATESPATENTS 2,664,966 1/1954 Moore ..55/236 3,177,634 4/1965 Latham, Jr. etal... .....55/236 3,199,270 8/1965 Oehlrich ..55/261 3,332,401 7/1967Lustenader 261/79.1 3,347,372 10/ 1967 Bouchillon ..209/21 1 3,379,0114/1968 Ohain et al. ..55/235 Primary ExaminerFrank W. Lutter AssistantExaminerBernard Nozick Attorney-Curt M. Avery, Arthur E. Wilfond,Herbert L. Lerner and Daniel J. Tick [5 7] ABSTRACT A tomadoflowapparatus for separating particulate substances, especially adhesiveliquids, from gases, comprises a cylindrical separator vessel with anaxial clean-gas outlet, a gas inlet duct coaxially opposite the outletand tangential gas inlets obliquely opposed to the flow direction of theinlet duct for producing in the vessel a tornado flow which causes theparticulate substance to be separated from the gas and carried outwardlyinto an annular interspace surrounding the axial inlet duet. Nozzledevices are provided for producing a veil of liquid in the tornadochamber or on the inner wall surface of the chamber. Preferably thenozzle devices comprise a spray nozzle coaxially mounted in the mouth ofthe inlet duct so as to produce a conical veil of liquid in the lowerregion of the vessel; and tangential nozzle means in the upper region ofthe vessel inject liquid to wet the inner wall of the vessel.

3 Claims, 1 Drawing Figure TORNADO-FLOW APPARATUS FOR SEPARATINGPARTICULATE SUBSTANCE FROM GASES, PARTICULARLY ADHESIVE LIQUIDS FROMGASES Our invention relates to tornado-flow apparatus for separatingparticulate matter from gases in which such matter is entrained. in amore particular, though exclusive aspect theinvention concernstornado-flow apparatus for separating adhesive liquids, such as paintsprays or other easily adhering substances from gases.

Tornado-flow apparatus of the kind here involved comprise a cylindricalvessel which forms a processing or tornado chamber proper and isprovided with a clean-gas-outlet duct in coaxial relation to the vessel.A gas inlet duct axially opposite the outlet duct may supply the gaswith the entrained matter to be separated. The vessel is furtherequipped with additional gas inlets which are inclined toward the gasinlet duct and generally extend tangentially to the processing chamberof the vessel. The gas supplied through the tangential and inclinedinlets may also consist ofa particleladen flow of gas. It is irrelevantwhether all or most of the particle laden gas is supplied through theaxially located inlet duct while an auxiliary gas flow is suppliedthrough the tangentially inclined inlets or whether, conversely, most orall of the flow of particleladen gas enters through the tangential andinclined inlets while a supply of clean gas or a smaller amount ofparticleladen gas passes through the axially located inlet duct. As aresult of the axial flow through the inlet duct and the tangential flowthrough the inclined inlets, there occurs in the vessel a so-calledtornado flow which is composed of an outer helical potential flow in thevicinity of the vessel walls and an inner helical rotational flow whichrotates in the same sense as the outer flow but advances in the axiallyopposite direction, the inner flow being comparable to the hose of anatural tornado. The particulate matter to be separated is carried inthe direction toward the inner peripheral surface of the processingvessel without normally reaching it and then passes downwardly in aregion between the outer helical flow and the inner helical flow untilit reaches a collecting gap space of annular shape which surrounds theaxially located gas inlet duct within the vessel. As to the physicalphenomena involved in the separating performance by tornado flow andalso with respect to the terminology herein applied, reference may behad to the more detailed explanations presented in US Pat. No. 3,199,268and No. 3,199,272, for example.

lt is an object of my invention to improve the efficacy and efficiencyof such tornado-flow separators with respect to the separation of solidparticles such as may occur as fly ash in the operation of incinerators.

Another object of my invention is to render tornado-flow apparatussuitable for a separation of adhesive liquids, for example paint sprayor other liquid particulate matter as occur in spray mists, from theentraining gas.

When adhesive liquids, for example paint sprays, oils or othersurface-protecting media, are to be separated from a gaseous carrier ina tornadoflow separator of the above-mentioned kind, there is the dangerof some of the liquid being thrown onto the inner wall surface of theprocessing vessel and adhering to that surface. The resultingaccumulation may cause clogging of the processing chamber. It istherefore among the more specific objects of my invention to more reliably prevent deposition of adhesive substance, particularly adhesiveliquids, on the inner wall surface of the processing chamber or on otherparts thereof.

To achieve the above-mentioned objects, and in accordance with a featureof my invention, I provide the tornado-flow separator vessel withliquid-supply means, and connect to the liquid-supply means a nozzledevice whose orifice means are open toward the interior of the vesseland directed toward the inner wall surface of the vessel for maintaininga veil of liquid. According to another feature of the invention, Iarrange a spray nozzle coaxially in the mouth of the axial gas inletpipe to produce a cone-shaped veil of liquid in the lower region of thetornado chamber. According to still another feature of the invention, Iprovide additional tangential nozzles in the upper region of the tornadochamber for supplying a liquid which causes wetting of the inner wallsurface of the processing vessel. Preferably, a tornado-flow separatoraccording to the invention is equipped with a spray-cone nozzle in thegas inlet tube at the bottom of the cylindrical tornado vessel and alsowith tangential liquid nozzles in the top portion of the vessel.

If the separator is to be used for the separation of solid particlesfrom gas, the wetting effected by the spray nozzle or the tangentialnozzles mentioned above, may be effected by using water. However, if thematter to be separated from the gas is paint or another aerosolconstituent insoluble in water, the gas supplied by either the spraynozzle or the lateral inlet may consist of a proper solvent for thematerial to be prevented from adhering to the inner wall surface of thevessel.

The particles to be separated out are seized and to a large extentagglomerated by the liquid veil produced by the nozzle in the gas inlettube. The veil thus contributes to more reliably separating theparticles without having the possibility of coming into contact with thewall of the tornado chamber. The spray nozzle preferably has an outercasing in the form of a cylindrical tube with a conically expandingaperture at the top and, coaxial therewith, a liquid-supply duct closedat the top and sealed to the bottom of the outer casing of the valve.The duct has radial bores in its upper region and carries avalveplate-shaped extension in or above the conically expanding apertureof the valve outer casing. Preferably, the outer casing of the valve ismade axially displaceable in relation to the liquid-supply duct, for thepurpose of adjusting the nozzle aperture and regulating the veil ofliquid.

For improved stimulation of the tornado flow, it is of advantage toprovide guide vanes in the mouth region of the axial gas inlet, betweenthe outer casing of the spray nozzle and the inner casing of the gasinlet duct, since these impart an initial twist to the gas-particlemixture. In order to prevent adhesive liquid from being deposited on theguide vanes, the lower edges thereof may be provided in the region offlow with a supply ofliquid extending over their entire width, so thatthe guide vanes are also wetted with a veil ofliquid.

The construction of operation of the invention will be explained ingreater detail with reference to an embodiment shown by way of exampleon the accompanying schematic drawing.

A gas-liquid mixture to be cleaned enters the tornado chamber in acylindrical vessel 1 axially from below through an inlet duct 2.Arranged on the vessel 1 and/or in a cover 22 thereof, above the mouth 5ofinlet duct 2, there are obliquely tangential nozzles 4 for producingan outer potential flow running helically downward in the region closeto the inner wall surface of the vessel. One portion of the potentialflow passes over the mouth 5 of the gas inlet duct 2 (through a vortexsink) to the axis of the tornado chamber, where it rises with theinflowing gas-liquid mixture in the form of a rotating flow to aclean-gas outlet 3. Above the mouth 5, the particles to be separated outare discharged (in a vortex source) toward the wall of the vessel 1 andare carried into an annular interstitial space 6 between the gas inletduct 2 and the inner wall of the vessel 1. From space 6 the collectedparticles are drained through an outlet 7 opening into a bunker, notshown. The outlet 7 may be arranged either vertically downward as shownor obliquely toward one side in a separate bunker. A diaphragm 8 isattached to gas inlet duct 2 in the annular space 6 in order to form anarrow annular gap between duct 2 and vessel 1 to thereby improve theseparating process.

According to the invention, a spray nozzle 9 is arranged coaxiallywithin the mouth area 5 of inlet duct 2. The nozzle produces anapproximately conical and upwardly widening veil of liquid in the lowerpart of the tornado chamber in vessel 1. A large part of the liquidparticles to be separated out are seized by this veil of liquid and arecarried to the wall of the vessel 1. While the veil of liquid alsoimpinges upon the middle or upper portion of the vessel wall and thusproduces a film of liquid running down the chamber wall, this filmconsists of a mixture of the liquid and the adhesive liquid or otherparticles to be separated out. This contributes to preventing adhesion,but the occurrence of deposits on the inner wall of the chamber may notalways be prevented entirelyv For this reason, additional tangentialnozzles 20, which may also be directed obliquely downward, are arrangedin the top portion of the tornado chamber, in order to supply anadditional flow of liquid. The entire inner casing of the vortex chamberis thereby wetted with a veil of liquid, thus fully obviating anyadhesion of particles to be separated and consequent blocking of theseparator chamber.

The spray nozzle 9 has an outer casing 10 in the form of a cylindricaltube with a conically expanding orifice 11 at the top, from which theliquid is sprayed into the tornado chamber. A liquid-supply duct 12,closed at the top, is arranged coaxially within the casing 10 in such amanner that an annular space 21 is left free between the valve outercasing 10 and the liquid-supply duct 12, this space being sealed in thebottom portion of the outer casing 10 by means of an internally threadedsealing ring 18 tightly screwed against the lower end of valve casing10. The top of duct 12 carries a plate-shaped extension 14 at theconical orifice 11 in valve casing 10.

The liquid flowing through a supply pipe 16, coaxial with inlet duct 2,into the duct 12 passes through radial bores 13 in the upper area of theduct 12, thence into the annular space 21 and through the orifice 11into the tornado chamber. For the purpose of adjusting the nozzleopening, the valve outer casing 10 is axially displaceable relative tothe liquid-supply duct 12. To this end, the valve casing 10 is connectedto the duct 12 by a screw thread 15 so that the valve casing may beadjusted at will.

For improved stimulation of the rotation of the gas-liquid mixture to becleaned, guide vanes 19 are arranged in mouth area 5 of the inlet duetpipe 2 between the spray nozzle 9 and the inner surface of the inletduct; the vanes 19 are shaped for imparting a twist to the incomingflow, thus contributing to the stimulation of the rotational flow.

To prevent the liquid particles from settling on the guide vanes 19 ofthe pretwisting nozzle, the outer casing 10 of the nozzle has radialbores in the region where the flow impinges upon the guide vanes, and aportion of the auxiliary liquid is sprayed onto the guide vanes throughlateral bores of an additional liquid-supply pipe 17 extending over theentire width of the guide vanes. Thus, the guide vanes are wetted with aveil of liquid. It is also possible to make the vanes 19 themselveshollow in their lower regions, allowing the liquid to escape from holestherein.

The invention is not restricted to separating out adhesive liquidparticles. It is also possible to separate mixtures of liquids ofdifferent densities, e.g., water-oi] mixtures, in a tornado flowseparator of this kind. Moreover, by utilizing the radial pressure dropin apparatus of this kind, liquids which are easy to vaporize may beseparated from liquids which are hard to vaporize. As mentioned,apparatus according to the invention is also applicable for separatingout very fine dust or other solid particles that need not issue from theseparator in dry condition. Aside from industrial purposes, theversatility as to the use of such apparatus makes them also advantageousfor air pollution control.

Upon a study of this disclosure, it will be obvious to those skilled inthe an that my invention permits of various modifications and may begiven embodiments other than illustrated and described herein, withoutdeparting from the essential features of my invention and within thescope of the claims annexed hereto.

We claim:

1. Tornado-flow apparatus for separating adhesive liquids from gases,comprising a cylindrical separator vessel having an axial clean-gasoutlet, a gas inlet duct coaxially opposite said outlet and forming anannular interspace between said duct and said vessel, said vessel havingtangential gas inlets obliquely opposed to the flow direction of saidinlet duct for producing in said vessel a rotating flow in the form ofan outer helical potential flow and an inner helical rotating flowturning in the same direction as said outer flow and advancing in anopposed axial flow direction whereby particles of liquid are separatedout of the gas and carried outwardly toward the inner wall surface ofthe vessel and into said interspace surrounding said axial intake duct,and outlet means adjacent said axial intake duct for dischargingseparated particles of liquid from said interspace, in combination withthe improvement comprising a spray nozzle having an adjustable nozzleaperture for producing a conical veil of liquid in the lower region ofsaid vessel directed toward said clean-gas outlet, said spray nozzlebeing mounted coaxially in the mouth of said axial inlet duct, meansadjacent said spray noule for imparting a twist to the incoming flow ofgas and liquid, and said vessel having additional tangential nozzlemeans for introduction of liquid to wet the inner wall of said vessel,said additional tangential nozzle means being provided in the upperregion of the said vessel, said spray nozzle comprising an outer casingin the form of a vertically extending cylindrical tube having a wall atthe top thereof formed with a conically expanding aperture, a verticallyextending liquid-supply duct coaxially located in said casing and closedat the top thereof, said liquid-supply duct forming with said casing anannular interspace sealed at the bottom thereof, said supply duct havinglateral bores in its upper region, and a plate-shaped extension mountedon top of said supply duct near said aperture.

2, ln apparatus according to claim I, said outer casing being axiallydisplaceable in relation to said liquid-supply duct for adjusting saidnozzle aperture.

3. Apparatus according to claim 1, comprising guide vanes for impartingan initial twist to the gas-liquid mixture, said vanes being situated inthe mouth region of said axial inlet duct between said outer casing ofsaid spray nozzle and the inner surface of said inlet duct and beingprovided at their lower edges with liquid supply means extending overthe transverse width of said respective vanes for wetting the vanesurfaces.

1. Tornado-flow apparatus for separating adhesive liquids from gases,comprising a cylindrical separator vessel having an axial clean-gasoutlet, a gas inlet duct coaxially opposite said outlet and forming anannular interspace between said duct and said vessel, said vessel havingtangential gas inlets obliquely opposed to the flow direction of saidinlet duct for producing in said vessel a rotating flow in the form ofan outer helical potential flow and an inner helical rotating flowturning in the same direction as said outer flow and advancing in anopposed axial flow direction whereby particles of liquid are separatedout of the gas and carried outwardly toward the inner wall surface ofthe vessel and into said interspace surrounding said axial intake duct,and outlet means adjacent said axial intake duct for dischargingseparated particles of liquid from said interspace, in combination withthe improvement comprising a spray nozzle having an adjustable nozzleaperture for producing a conical veil of liquid in the lower region ofsaid vessel directed toward said clean-gas outlet, said spray nozzlebeing mounted coaxially in the mouth of said axial inlet duct, meansadjacent said spray nozzle for imparting a twist to the incoming flow ofgas and liquid, and said vessel having additional tangential nozzlemeans for introduction of liquid to wet the inner wall of said vessel,said additional tangential nozzle means being provided in the upperregion of the said vessel, said spray nozzle comprising an outer casingin the form of a vertically extending cylindrical tube having a wall atthe top thereof formed with a conically expanding aperture, a verticallyextending liquid-supply duct coaxially located in said casing and closedat the top thereof, said liquid-supply duct forming with Said casing anannular interspace sealed at the bottom thereof, said supply duct havinglateral bores in its upper region, and a plate-shaped extension mountedon top of said supply duct near said aperture.
 2. In apparatus accordingto claim 1, said outer casing being axially displaceable in relation tosaid liquid-supply duct for adjusting said nozzle aperture.
 3. Apparatusaccording to claim 1, comprising guide vanes for imparting an initialtwist to the gas-liquid mixture, said vanes being situated in the mouthregion of said axial inlet duct between said outer casing of said spraynozzle and the inner surface of said inlet duct and being provided attheir lower edges with liquid supply means extending over the transversewidth of said respective vanes for wetting the vane surfaces.